RE: Difference between RPG III and RPG IV with CHAIN

[<lgoodbar@xxxxxxxxxxxxxx>]

It "reads" wrong to me. To me CHAIN implies an intent to retrieve one
row and only one row, while SETxx/READE implies an intent of reading a
group of rows (1+). I also do not like mixing CHAIN as the prime and
READx as the looping construct. It looks like a mixed metaphor.

It's more personal preference than anything, likely due to starting with
RPG/IV (mid-1990s). 

Thanks,
Loyd

"If we hit that bull's eye, the rest of the dominoes will fall like a
house of cards. Checkmate." --Zapp Brannigan




-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Tom Liotta
Sent: Saturday, November 28, 2009 4:20 AM
To: midrange-l@xxxxxxxxxxxx
Subject: Re: Difference between RPG III and RPG IV with CHAIN

Loyd Goodbar wrote:

> IMO, chain is the wrong tool for looking at files with duplicate keys.
I've
> only used chain when key values are unique, or SETxx and READxx for
> duplicate-keyed files. Know your data...

Why? Especially for duplicate keys, CHAIN plus READE can work great. 
The CHAIN not only does the SETLL but also a 'priming' READ for a 
loop. Just wondering why it should be avoided.

Tom Liotta

p.s. Yes... late response. I'm almost at the point of "one list per 
week".